Preventing return-oriented programming exploits by identifying a set of contiguous computer software instructions extending from a first location within a computer memory to a second location within the computer memory, where the set of computer software instructions includes a return-oriented programming gadget, copying the set of computer software instructions to extend from a third location within the computer memory to a fourth location within the computer memory, placing a branching instruction at the first memory location, where the branching instruction branches to the third location, appending a return branching instruction to the copy of the set of computer software instructions, where the return branching instruction branches to a fifth location within the computer memory that immediately follows the second location, and overwriting at least a portion of the return-oriented programming gadget between the first location and the second location.